WO 2011/073154 discloses a number of tetrahydropyranyl-methyl-amino-(hetero)aryl-amides without disclosing any specific salt or crystal form of the compounds exemplified therein. Among others, WO 2011/073154 discloses compound I

Compounds disclosed in WO 2011/073154 are potent CCR2 antagonists. However, in order to prove to be developable for use as a medicament in a human, a drug substance and its solid form must, in addition to in vitro and in vivo pharmacokinetic and pharmacological properties and safety profile, fulfil a series of criteria with regard to the requirements of chemistry, manufacturing and controls (CMC) such as solid form characteristics, purity, drying times, filterability, stability, thermal stability, hygroscopicity, reproducibility and further physicochemical properties including solubility and intrinsic dissolution rate.
One of the biggest challenges in the course of the development of a drug product for medical use in humans is to identify a drug substance which is potent, efficacious, fulfils safety requirements and simultaneously has a solid form suitable for human drug development, i.e., fulfilling all the above mentioned criteria cumulatively. This is because each and every solid form, salt and polymorphic form thereof has physicochemical and pharmacokinetic properties which are just as unforeseeable as unexpected.
Furthermore, due to the unpredictable and unexpected nature of the solid, salt and polymorphic forms, there is neither generic nor specific guidance for the skilled person how to design a solid form with the desired characteristics. Therefore, extensive and creative research and experimentation is essential to arrive at the specific solid form of a selected drug substance that fulfils all requirements. Optimization of one crucial parameter often results in the deterioration of another or other parameter(s).